scholarly journals SPACE TIME COVARIANCE OF CANONICAL QUANTIZATION OF GRAVITY: A (FORMAL) GENERAL RESULT AND THE (RIGOROUS) EXPLICIT CASE OF 2+1 QUANTUM COSMOLOGY

2013 ◽  
Vol 1 (2) ◽  
pp. 112-128 ◽  
Author(s):  
Christodoulakis
Keyword(s):  
General Result ◽  
Quantum Cosmology ◽  
Canonical Quantization ◽  
Space Time ◽  
Quantization Of Gravity

scholarly journals THE ROLE OF THE TIME GAUGE IN THE SECOND-ORDER FORMALISM

2008 ◽  
Vol 23 (08) ◽  
pp. 1214-1217
Author(s):  
FRANCESCO CIANFRANI ◽  
GIOVANNI MONTANI
Keyword(s):  
Canonical Quantization ◽  
Space Time ◽  
Second Order ◽  
Lorentz Frame ◽  
Quantization Of Gravity ◽  
Gauge Fixing ◽  
Time Splitting

We perform a canonical quantization of gravity in a second-order formulation, taking as configuration variables those describing a 4-bein, not adapted to the space-time splitting. We outline how, neither if we fix the Lorentz frame before quantizing, nor if we perform no gauge fixing at all, is invariance under boost transformations affected by the quantization.

Conditional interpretation of time in quantum gravity and a time operator in relativistic quantum mechanics

2020 ◽  
Vol 35 (21) ◽  
pp. 2050114
Author(s):  
M. Bauer ◽  
C. A. Aguillón ◽  
G. E. García
Keyword(s):  
Quantum Mechanics ◽  
Quantum Gravity ◽  
Relativistic Quantum ◽  
Canonical Quantization ◽  
Time Operator ◽  
Relativistic Quantum Mechanics ◽  
Problem Of Time ◽  
Quantization Of Gravity ◽  
Dynamical Time ◽  
Spatial Coordinates

The problem of time in the quantization of gravity arises from the fact that time in Schrödinger’s equation is a parameter. This sets time apart from the spatial coordinates, represented by operators in quantum mechanics (QM). Thus “time” in QM and “time” in general relativity (GR) are seen as mutually incompatible notions. The introduction of a dynamical time operator in relativistic quantum mechanics (RQM), that follows from the canonical quantization of special relativity and that in the Heisenberg picture is also a function of the parameter [Formula: see text] (identified as the laboratory time), prompts to examine whether it can help to solve the disfunction referred to above. In particular, its application to the conditional interpretation of time in the canonical quantization approach to quantum gravity is developed.

Canonical quantization of gravity and quantum geometrodynamics

1986 ◽  
Vol 29 (3) ◽  
pp. 187-199 ◽  
Author(s):  
A. O. Barvinskii ◽  
V. N. Ponomarev
Keyword(s):  
Canonical Quantization ◽  
Quantization Of Gravity ◽  
Quantum Geometrodynamics

TIME AND INTERPRETATIONS OF QUANTUM GRAVITY

2011 ◽  
Vol 20 (supp01) ◽  
pp. 3-86 ◽  
Author(s):  
KAREL V. KUCHAŘ
Keyword(s):  
Quantum Gravity ◽  
Physical Interpretation ◽  
Canonical Quantization ◽  
The State ◽  
Quantization Of Gravity

In canonical quantization of gravity, the state functional does not seem to depend on time. This hampers the physical interpretation of quantum gravity. I critically examine ten major attempts to circumvent this problem and discuss their shortcomings.

scholarly journals The time measurement problem in quantum cosmology

2017 ◽  
Vol 26 (12) ◽  
pp. 1743011
Author(s):  
Nirmalya Kajuri
Keyword(s):  
Quantum Cosmology ◽  
Measurement Problem ◽  
Time Measurement ◽  
Conditional Probabilities ◽  
Problem Of Time ◽  
Quantization Of Gravity ◽  
Canonical Approach

In the canonical approach to quantization of gravity, one often uses relational clock variables and an interpretation in terms of conditional probabilities to overcome the problem of time. In this essay, we show that these suffer from serious conceptual issues.

scholarly journals TIME AND TACHYON

2003 ◽  
Vol 18 (26) ◽  
pp. 4869-4888 ◽  
Author(s):  
ASHOKE SEN
Keyword(s):  
Field Theory ◽  
Scalar Field ◽  
Quantum Gravity ◽  
Quantum Cosmology ◽  
Canonical Quantization ◽  
Recent Analysis ◽  
Late Time ◽  
Classical Dynamics ◽  
One To One ◽  
Definition Of

Recent analysis suggests that the classical dynamics of a tachyon on an unstable D-brane is described by a scalar Born–Infeld type action with a runaway potential. The classical configurations in this theory at late time are in one to one correspondence with the configuration of a system of noninteracting (incoherent), nonrotating dust. We discuss some aspects of canonical quantization of this field theory coupled to gravity, and explore, following an earlier work on this subject, the possibility of using the scalar field (tachyon) as the definition of time in quantum cosmology. At late "time" we can identify a subsector in which the scalar field decouples from gravity and we recover the usual Wheeler–de Witt equation of quantum gravity.

On the meaning of the wave function of the Universe

2019 ◽  
Vol 28 (13) ◽  
pp. 1941009 ◽  
Author(s):  
Tatyana P. Shestakova
Keyword(s):  
Wave Function ◽  
Quantum Cosmology ◽  
Quantum Processes ◽  
Extended Phase ◽  
Quantization Of Gravity ◽  
Present Universe ◽  
Objective Description ◽  
The Universe ◽  
Quantum Geometrodynamics ◽  
Space Approach

The meaning of the wave function of the Universe was actively discussed in 1980s. In most works on quantum cosmology, it is accepted that the wave function is a probability amplitude for the Universe to have some space geometry, or to be found in some point of the Wheeler superspace. It seems that the wave function gives maximally objective description compatible with quantum theory. However, the probability distribution does not depend on time and does not take into account the existing of our macroscopic evolving Universe. What we wish to know is how quantum processes in the Early Universe determined the state of the present Universe in which we are able to observe macroscopic consequences of these quantum processes. As an alternative to the Wheeler–DeWitt quantum geometrodynamics, we consider the picture that can be obtained in the extended phase space approach to quantization of gravity. The wave function in this approach describes different states of the Universe which correspond to different stages of its evolution.

Sign in / Sign up

Export Citation Format

Share Document